Blower and vacuum cleaner

ABSTRACT

A blower includes an impeller, a motor, and a housing. The impeller is able to rotate around a center axis extending vertically. The motor includes a rotor connected to the impeller and a stator facing the rotor in a radial direction. The housing accommodates at least a part of the motor. The housing includes a first housing part, a second housing part, and a rib. The first housing part is disposed on an outer side in the radial direction of the stator and a radial inner surface thereof forms a flow passage. The second housing part is disposed on an inner side in the radial direction of the first housing part. The rib connects the first housing part and the second housing part. A bottom surface of the rib includes a bottom-surface first area that extends downward toward a front side in a rotational direction of the impeller.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119 to Japanese Application No. 2019-001903 filed on Jan. 9, 2019, the entire content of which is incorporated herein by reference.

BACKGROUND Technical Field

The disclosure relates to a blower and a vacuum cleaner.

Background

In an axial ventilator which is known in the related art, an axial fan is disposed in a tubular casing. One side of the axial fan is connected to an electric motor. A cylindrical motor cover is attached to an outer circumferential part of the electric motor. A plurality of fixing legs that protrudes in a radial direction is provided on an outer surface of the motor cover. A tip of each fixing leg is fixed to an inner surface of the casing. The motor cover is fixed and supported to the casing by the fixing legs.

In the axial ventilator which is known in the related art, since the fixing legs are disposed in the casing, there is a likelihood that air-blowing resistance in the casing will increase, and air-blowing efficiency will decrease.

SUMMARY

According to an embodiment of the disclosure, there is provided a blower including an impeller, a motor, and a housing. The impeller is able to rotate around a center axis extending vertically. The motor includes a rotor connected to the impeller and a stator facing the rotor in a radial direction. The housing accommodates at least a part of the motor. The housing includes a first housing part, a second housing part, and a rib. The first housing part is disposed on an outer side in the radial direction of the stator and a radial inner surface thereof forms a flow passage. The second housing part is disposed on an inner side in the radial direction of the first housing part. The rib connects the first housing part and the second housing part. A bottom surface of the rib includes a bottom-surface first area that extends downward toward a front side in a rotational direction of the impeller.

The above and other elements, features, steps, characteristics, and advantages of the disclosure will become more apparent from the following detailed description of the embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a longitudinal section of a blower according to an embodiment of the disclosure;

FIG. 2 is an exploded perspective view of the blower according to the embodiment of the disclosure;

FIG. 3 is a perspective view of a stator core according to the embodiment of the disclosure;

FIG. 4 is a perspective view of an upper housing according to the embodiment of the disclosure;

FIG. 5 is a perspective view of a lower housing according to the embodiment of the disclosure;

FIG. 6 is a plan view of the upper housing according to the embodiment of the disclosure;

FIG. 7 is a schematic longitudinal sectional view taken along line X-X in FIG. 6;

FIG. 8 is a schematic longitudinal sectional view taken along line Y-Y in FIG. 6;

FIG. 9 is a longitudinal sectional view illustrating a relationship between a stator and a housing;

FIG. 10 is a transverse sectional view illustrating a relationship between an insulator and the upper housing;

FIG. 11 is a schematic longitudinal section view illustrating a first modified example of the blower according to the embodiment of the disclosure;

FIG. 12 is a schematic longitudinal section view illustrating a second modified example of the blower according to the embodiment of the disclosure;

FIG. 13 is a schematic longitudinal section view illustrating a third modified example of the blower according to the embodiment of the disclosure; and

FIG. 14 is a perspective view of a vacuum cleaner according to the embodiment of the disclosure.

DETAILED DESCRIPTION

Hereinafter, an exemplary embodiment of the disclosure will be described in detail with reference to the accompanying drawings. In describing a blower 100 in this specification, a direction which is parallel to a center axis C of a motor 2 which is included in the blower 100 is defined as an “axial direction,” a direction which is perpendicular to the center axis C is defined as a “radial direction,” and a direction along an arc centered on the center axis C is defined as a “circumferential direction.” In this specification, shapes or positional relationships of parts will be described with reference to a state in which the axial direction is set as a vertical direction and an impeller 1 is located above the motor 2.

In describing a vacuum cleaner 200 in this specification, shapes or positional relationships of parts will be described with reference to a state in which a direction toward a floor surface F (a cleaning surface) in FIG. 14 is called a “lower side” and a direction away from the floor surface F is called an “upper side.” These directions are names which are simply used for description and do not limit actual positional relationships and directions.

In this specification, “upstream” and “downstream” represent upstream and downstream in a flowing direction of an air flow 300 which is generated when an impeller 1 rotates. In this specification, a section parallel to the axial direction is referred to as a “longitudinal section” and a section perpendicular to the axial direction is referred to as a “transverse section.” “Parallel,” as used in this specification, includes substantially parallel. “Perpendicular,” as used in this specification, includes substantially perpendicular.

FIG. 1 is a perspective view illustrating a longitudinal section of a blower 100 according to an embodiment of the disclosure. FIG. 2 is an exploded perspective view of the blower 100 according to the embodiment of the disclosure. As illustrated in FIGS. 1 and 2, the blower 100 includes an impeller 1, a motor 2, and a housing 3. The blower 100 further includes a diffuser 4, an impeller cover 5, and a circuit board 6.

The impeller 1 can rotate around a center axis C extending vertically. The impeller 1 is formed of, for example, a metallic member. An outer edge of the impeller 1 in the radial direction has a circular shape in a plan view in the axial direction. The impeller 1 includes a base plate 11, a plurality of vanes 12, a shroud 13, and a hub 14.

The base plate 11 is disposed in a lower part of the impeller 1. The base plate 11 extends in the radial direction from the center axis C. The base plate 11 is a disc-shaped member. The base plate 11 supports lower parts of the vanes 12.

The plurality of vanes 12 is disposed on the base plate 11. The plurality of vanes 12 is arranged in the circumferential direction on the top surface of the base plate 11. The lower part of each of the plurality of vanes 12 is connected to the base plate 11. The upper part of each of the plurality of vanes 12 is connected to the shroud 13. Each vane 12 is a plate-shaped member standing vertically upright. Each vane 12 extends from an inner side in the radial direction to an outer side in the radial direction and is curved in the circumferential direction.

The shroud 13 is disposed above the plurality of vanes 12. The shroud 13 has an annular shape centered on the center axis C in a plan view in the axial direction. The shroud 13 is formed of an annular plate-shaped member and is specifically curved upward from an outer end in the radial direction to the inner side in the radial direction. The shroud 13 includes a shroud intake port 13 a which opens vertically. The shroud intake port 13 a is disposed at the center of the shroud 13. The shroud 13 supports the upper parts of the vanes 12.

The hub 14 is disposed at the center of the base plate 11 in the vicinity of the center axis C of the base plate 11. The hub 14 has an annular shape centered on the center axis C in a plan view in the axial direction.

As illustrated in FIGS. 1 and 2, the motor 2 includes a rotor 21 and a stator 22. The motor 2 further includes a bearing 23.

The rotor 21 is connected to the impeller 1. The rotor 21 includes a shaft 211 and a magnet 212.

The shaft 211 is disposed along the center axis C extending vertically. The shaft 211 is a pillar-shaped member which is formed of, for example, a metal. The upper part of the shaft 211 vertically penetrates the base plate 11 and the hub 14 and is fixed to the hub 14. That is, the impeller 1 is fixed to the upper part of the shaft 211.

The magnet 212 has a tubular shape extending in the axial direction. The magnet 212 is disposed on the outer side in the radial direction of the shaft 211 and is fixed to the shaft 211. An N pole and an S pole are alternately arranged in the circumferential direction on an outer surface of the magnet 212 in the radial direction.

The stator 22 is an armature that generates magnetic flux depending on a driving current. The stator 22 faces the rotor 21 in the radial direction. In this embodiment, the stator 22 is disposed on the outer side in the radial direction of the rotor 21. The stator 22 includes a stator core 221 and an insulator 222. The stator 22 further includes a coil 223.

The stator core 221 is a stacked body which is formed by stacking electromagnetic steel sheets in the axial direction. Here, the stator core 221 may be a single member which is formed, for example, by performing firing, casting, or the like on a powder. The stator core 221 may be formed by bonding a plurality of core pieces. FIG. 3 is a perspective view of the stator core 221 according to the embodiment of the disclosure.

As illustrated in FIG. 3, the stator core 221 includes a core back 2211 and a plurality of teeth 2212. The core back 2211 has an annular shape centered on the center axis C. The teeth 2212 protrude inward in the radial direction from the core back 2211. The plurality of teeth 2212 is arranged in the circumferential direction. In this embodiment, the number of teeth 2212 is three. The three teeth 2212 are arranged at regular intervals in the circumferential direction. The number of teeth 2212 may not be three.

A plurality of stator core holes 2213 is formed in the core back 2211. The stator core holes 2213 are formed to extend in the axial direction. The stator core holes 2213 are disposed on the outer side in the radial direction of the teeth 2212. The number of stator core holes 2213 is the same as the number of teeth 2212. In this embodiment, the number of stator core holes 2213 is three. Here, the number of stator core holes 2213 may not be three.

The insulator 222 covers at least a part of the stator core 221. The insulator 222 is formed of an insulating member of a resin or the like. In this embodiment, the insulator 222 includes an upper insulator 222U and a lower insulator 222L. The upper insulator 222U covers the stator core 221 from the upper side. The lower insulator 222L covers the stator core 221 from the lower side. Here, the insulator 222 may be integrally formed with the stator core 221 by insert molding.

In this embodiment, a radial outer end surface of the core back 2211 and radial inner end surfaces of the teeth 2212 are not covered by the insulator 222 but are exposed.

The coil 223 is formed by winding a wire around the stator core 221 with the insulator 222 interposed therebetween. Specifically, the coil 223 is formed by winding a wire around each tooth 2212 with the insulator 222 interposed therebetween. That is, the stator 22 includes a plurality of coils 223. The plurality of coils 223 is arranged at regular intervals in the circumferential direction. In this embodiment, the number of coils 223 is three. Here, the number of coils 223 may not be three.

The bearing 23 supports the rotor 21 to be rotatable around the center axis C with respect to the stator 22. In this embodiment, the bearing 23 includes an upper bearing 23U and a lower bearing 23L. The upper bearing 23U is disposed above the stator 22. The lower bearing 23L is disposed below the stator 22.

In this embodiment, the upper bearing 23U and the lower bearing 23L are rolling bearings. Each of the upper bearing 23U and the lower bearing 23L includes an inner ring 231 and an outer ring 232. The inner ring 231 is disposed on the outer side in the radial direction of the shaft 211 and is fixed to the shaft 211. The outer ring 232 is disposed on the outer side in the radial direction of the inner ring 231 and is fixed to the housing 3. Rolling members such as balls are disposed between the inner ring 231 and the outer ring 232 in the radial direction. The inner ring 231 is provided to be rotatable with respect to the outer ring 232. The number and type of the bearings 23 may be changed from the configuration in this embodiment. The motor 2 may include a sleeve bearing instead of the rolling bearing.

The housing 3 accommodates at least a part of the motor 2 therein. The housing 3 is formed of, for example, a metal such as aluminum. Here, the housing 3 may be formed of a material such as a resin instead of a metal. In this embodiment, the housing 3 includes an upper housing 3U and a lower housing 3L. The upper housing 3U surrounds the upper part of the motor 2. The lower housing 3L surrounds the lower part of the motor 2.

FIG. 4 is a perspective view of the upper housing 3U according to the embodiment of the disclosure. As illustrated in FIGS. 1 and 4, the upper housing 3U includes a first housing part 31, a second housing part 32, and a rib 33. That is, the housing 3 includes the first housing part 31, the second housing part 32, and the rib 33. In this embodiment, the first housing part 31, the second housing part 32, and the rib 33 are formed of a single member. Accordingly, in comparison with a case in which a plurality of members is combined, it is possible to enhance strength of the upper housing 3U.

The first housing part 31 is disposed on the outer side of the stator 22 in the radial direction. As illustrated in FIG. 1, a radial inner surface of the first housing part 31 forms a flow passage 101. The flow passage 101 is a passage of an air flow 300 which is generated by rotation of the impeller 1. Specifically, the first housing part 31 has a tubular shape that extends in the axial direction from the center axis C. The first housing part 31 faces the stator 22 in the radial direction.

The second housing part 32 is disposed on the inner side of the first housing part 31 in the radial direction. In this embodiment, the second housing part 32 has a disc shape. The second housing part 32 is disposed above the first housing part 31. The second housing part 32 faces the stator 22 in the axial direction. The second housing part 32 is disposed above the stator 22.

An upper-housing recessed part 321 that is recessed downward in the axial direction is formed at the center of the top surface of the second housing part 32. The upper-housing recessed part 321 has a circular shape centered on the center axis C in a plan view when seen from the upper side in the axial direction. The upper bearing 23U is inserted into the upper-housing recessed part 321. The radial inner surface of the upper-housing recessed part 321 is in contact with a radial outer surface of the outer ring 232 of the upper bearing 23U in the radial direction and the upper bearing 23U is fixed to the upper housing 3U.

The rib 33 connects the first housing part 31 and the second housing part 32. In this embodiment, the rib 33 connects the radial inner surface of the first housing part 31 and the radial outer surface of the second housing part 32. The rib 33 extends inward in the radial direction from the radial outer surface of the second housing part 32 below the second housing part 32. As illustrated in FIG. 1, a rib recessed part 331 that is recessed upward in the axial direction is provided on the bottom surface of the rib 33.

In this embodiment, the number of ribs 33 is greater than two and, specifically, the number of ribs 33 is three. Three ribs 33 are arranged at regular intervals in the circumferential direction. Here, the number of ribs 33 may not be three and may be one.

In this embodiment, as illustrated in FIG. 1, the upper housing 3U further includes an upper tubular part 34. The upper tubular part 34 has a tubular shape extending downward in the axial direction from the bottom surface of the second housing part 32. The upper tubular part 34 is formed of the same member as the second housing part 32. The upper tubular part 34 is disposed on the inner side in the radial direction of the stator 22. A top-surface opening of the upper tubular part 34 is connected to an opening which is formed on the bottom wall of the upper-housing recessed part 321. The shaft 211 is inserted into the upper tubular part 34 and the upper-housing recessed part 321, and the upper part thereof protrudes upward from the top surface of the upper housing 3U.

FIG. 5 is a perspective view of the lower housing 3L according to the embodiment of the disclosure. As illustrated in FIGS. 1 and 5, the lower housing 3L includes a lower-housing body part 35 and a plurality of leg parts 36. In this embodiment, the number of leg parts 36 is three. Three leg parts 36 are arranged at regular intervals in the circumferential direction. Here, the number of leg parts 36 may not be three. In this embodiment, the lower-housing body part 35 and the plurality of leg parts 36 are formed of a single member. Accordingly, in comparison with a case in which a plurality of members is combined, it is possible to enhance strength of the lower housing 3L.

The lower-housing body part 35 includes a lower annular part 351, a first lower tubular part 352, and a second lower tubular part 353. The lower annular part 351 has an annular shape centered on the center axis C. The first lower tubular part 352 and the second lower tubular part 353 have a tubular shape extending in the axial direction from the center axis C.

The first lower tubular part 352 is disposed on the inner side in the radial direction of the lower annular part 351. The first lower tubular part 352 is connected to the lower annular part 351 by a first connection part 354 that is disposed between the lower annular part 351 and the first lower tubular part 352 in the radial direction. The second lower tubular part 353 has a diameter smaller than that of the first lower tubular part 352 and is disposed above the first lower tubular part 352. The second lower tubular part 353 is connected to the first lower tubular part 352 by a second connection part 355 that extends inward in the radial direction from the upper end of the first lower tubular part 352. The second lower tubular part 353 is disposed on the inner side in the radial direction of the stator 22. The shaft 211 is inserted into the first lower tubular part 352 and the second lower tubular part 353. The lower bearing 23L is inserted into the first lower tubular part 352. A radial inner surface of the first lower tubular part 352 is in contact with a radial outer surface of the outer ring 232 of the lower bearing 23L, and the lower bearing 23L is fixed to the lower housing 3L.

Each leg part 36 includes a leg-part outer wall part 361, a pair of leg-part side wall parts 362, and a leg-part upper wall part 363. The leg-part outer wall part 361 is disposed on the outer side in the radial direction of the lower annular part 351 and extends in the axial direction. The pair of leg-part side wall parts 362 faces each other in the circumferential direction. One of the pair of leg-part side wall parts 362 connects one end in the circumferential direction of the leg-part outer wall part 361 to the lower annular part 351. The other of the pair of leg-part side wall parts 362 connects the other end in the circumferential direction of the leg-part outer wall part 361 to the lower annular part 351. The leg-part upper wall part 363 extends inward in the radial direction from a lightly lower side of the upper end of the leg-part outer wall part 361. Two ends in the circumferential direction of the leg-part upper wall part 363 are connected to the upper ends of the pair of leg-part side wall parts 362. A leg-part hole 364 extending in the axial direction is formed in the leg-part upper wall part 363.

As illustrated in FIG. 1, the stator 22 is disposed between the upper housing 3U and the lower housing 3L in the axial direction. The stator 22 is fixed to the upper housing 3U and the lower housing 3L by a fixing member 7. In this embodiment, the fixing member 7 is a screw. The fixing member 7 is inserted into the leg-part hole 364, the stator core hole 2213, and the rib recessed part 331 from the lower side of the lower housing 3L. The fixing member 7 may be a rivet or the like instead of a screw.

The diffuser 4 includes a first diffuser tubular part 41, a second diffuser tubular part 42, and a plurality of stationary vanes 43. In this embodiment, the first diffuser tubular part 41, the second diffuser tubular part 42, and the plurality of stationary vanes 43 are formed of a single member. Here, at least one member of these members may be a separate member. The diffuser 4 may be formed of, for example, a resin or a metal.

The first diffuser tubular part 41 is disposed on the outer side in the radial direction of the second housing part 32. The first diffuser tubular part 41 has a tubular shape extending in the axial direction from the center axis C. The radial inner surface of the first diffuser tubular part 41 is in contact with the radial outer surface of the second housing part 32 in the radial direction.

The second diffuser tubular part 42 is disposed on the outer side in the radial direction of the first diffuser tubular part 41. The second diffuser tubular part 42 has a tubular shape extending in the axial direction from the center axis C. The second diffuser tubular part 42 is disposed above the first housing part 31. The bottom surface of the second diffuser tubular part 42 is in contact with the top surface of the first housing part 31 in the axial direction.

The top surface of the first diffuser tubular part 41 and the top surface of the second diffuser tubular part 42 have the same position in the axial direction. The first diffuser tubular part 41 has a length in the axial direction greater than that of the second diffuser tubular part 42. The lower end of the first diffuser tubular part 41 is disposed below the lower end of the second diffuser tubular part 42.

The plurality of stationary vanes 43 is arranged in the circumferential direction between the first diffuser tubular part 41 and the second diffuser tubular part 42 in the radial direction. Specifically, the plurality of stationary vanes 43 is arranged at regular intervals in the circumferential direction. Each stationary vane 43 extends in the axial direction. Specifically, each stationary vane 43 is formed in a plate shape and is inclined upward in the direction opposite to the rotational direction R (see FIG. 1) of the impeller 1. The impeller 1 side of each stationary vane 43 is curved to be convex.

The radial inner surface of each stationary vane 43 is in contact with the radial outer surface of the first diffuser tubular part 41. The radial outer surface of each stationary vane 43 is connected to the radial inner surface of the second diffuser tubular part 42. Between the first diffuser tubular part 41 and the second diffuser tubular part 42 in the radial direction, a part in which the plurality of stationary vanes 43 is not provided constitutes a flow passage 101 in which air flows. The plurality of stationary vanes 43 rectifies an air flow 300 passing through the flow page 101 and guides the air flow 300 downward.

As described above, the blower 100 further includes a plurality of stationary vanes 43 which is arranged in the circumferential direction above the rib 33. Since the plurality of stationary vanes 43 is provided, it is possible to enhance air-blowing efficiency of the blower 100.

The impeller cover 5 is disposed above the impeller 1. The impeller cover 5 accommodates the impeller 1 therein. The impeller cover 5 can be formed of, for example, a resin or a metal. The impeller cover 5 has a tubular shape that is tapered upward with respect to the center axis C. A radial inner surface of the impeller cover 5 is in contact with the radial outer surfaces of the second diffuser tubular part 42 and the first housing part 31. The impeller cover 5 is fixed to the diffuser 4 and the upper housing 3U.

The impeller cover 5 includes a cover intake port 5 a that is vertically open. The cover intake port 5 a is disposed at the center of the upper end of the impeller cover 5. The lower part of the cover intake port 5 a overlaps the upper part of the shroud intake port 13 a in the axial direction. The outer diameter of the lower part of the cover intake port 5 a is smaller than the inner diameter of the upper part of the shroud intake port 13 a.

The circuit board 6 is fixed to the lower housing 3L. Specifically, the circuit board 6 is fixed to the plurality of leg parts 36. For example, circuits for driving the motor 2 such as a power supply circuit and a control circuit are formed in the circuit board 6. As illustrated in FIG. 2, an electrical connection part 61 that is electrically connected to the coil 223 is disposed in the circuit board 6. The electrical connection part 61 may be, for example, a tap terminal. In this embodiment, the number of electrical connection parts 61 is three, and three electrical connection parts 61 are arranged at regular intervals in the circumferential direction. The number of electrical connection parts 61 may not be three.

When the impeller 1 is rotationally driven by the motor 2, air is sucked into the impeller 1 from the cover intake port 5 a of the impeller cover 5 and an air flow 300 is generated. The air sucked into the impeller 1 is blown out outward in the radial direction of the impeller 1 with rotation of the impeller 1. The air blown out outward in the radial direction of the impeller 1 is guided downward by a flow passage 101 which is constituted by the impeller cover 5, the diffuser 4, and the upper housing 3U. A part of the air flow 300 which is blown out downward from the lower end of the upper housing 3U flows to the outside of the blower 100 and the other flows to the circuit board 6. The circuit board 6 is cooled by the air flow 300.

FIG. 6 is a plan view of the upper housing 3U according to the embodiment of the disclosure. FIG. 7 is a schematic longitudinal sectional view taken along line X-X in FIG. 6. FIG. 8 is a schematic longitudinal sectional view taken along line Y-Y in FIG. 6. In FIG. 7, reference sign R represents the rotational direction of the impeller 1.

As illustrated in FIG. 7, the bottom surface of the rib 33 includes a bottom-surface first area 332 that extends downward toward a front side in the rotational direction R of the impeller 1. According to this configuration, the bottom surface of the rib 33 has a shape that can smoothly guide the air flow 300 which is generated due to rotation of the impeller 1. Accordingly, when the impeller 1 rotates, it is possible to reduce air-blowing resistance and to enhance air-blowing efficiency.

In this embodiment, the bottom-surface first area 332 is formed on a part of the bottom surface of the rib 33. The bottom-surface first area 332 is disposed at an end on the rear side in the rotational direction R of the impeller 1 on the bottom surface of the rib 33. The bottom-surface first area 332 may be an inclined surface or a curved surface. The bottom-surface first area 332 may be a combination of an inclined surface and a curved surface. In this embodiment, the bottom-surface first area 332 is a curved surface which is convex downward.

As illustrated in FIG. 7, the bottom surface of the rib 33 includes a bottom-surface second area 333 that extends upward toward the front side in the rotational direction R of the impeller 1 on the front side of the bottom-surface first area 332 in the rotational direction R of the impeller 1. By providing the bottom-surface second area 333, it is possible to curb occurrence of turbulence below the rib 33. Accordingly, it is possible to enhance air-blowing efficiency of the blower 100.

Specifically, the bottom-surface second area 333 is disposed at an end on the front side in the rotational direction R of the impeller 1 on the bottom surface of the rib 33. The bottom-surface second area 333 may be an inclined surface or a curved surface. The bottom-surface second area 333 may be a combination of an inclined surface and a curved surface. In this embodiment, the bottom-surface second area 333 is a curved surface which is convex downward. On the bottom surface of the rib 33, the bottom-surface first area 332 and the bottom-surface second area 333 are connected to each other via a plane. The bottom-surface second area 333 may not be disposed on the bottom surface of the rib 33.

An axial distance L1 between the upper end and the lower end of the bottom-surface first area 332 is larger than an axial distance L2 between the upper end and the lower end of the bottom-surface second area 333. Accordingly, it is possible to achieve an effect of smoothly guiding the air flow 300 using the bottom-surface first area 332 and an effect of curbing occurrence of turbulence using the bottom-surface second area 333 with good balance. That is, it is possible to enhance air-blowing efficiency of the blower 100.

As illustrated in FIG. 7, at least a part of the top surface of the rib 33 extends downward toward the front side in the rotational direction R of the impeller 1. According to this configuration, the top surface of the rib 33 has a shape that can smoothly guide the air flow 300 which is generated due to rotation of the impeller 1. Accordingly, when the impeller 1 rotates, it is possible to reduce air-blowing resistance and to enhance air-blowing efficiency.

In this embodiment, the top surface of the rib 33 includes a top-surface first area 334 and a top-surface second area 335. The top-surface first area 334 extends downward toward the front side in the rotational direction R of the impeller 1. The top-surface first area 334 is an inclined surface. Here, the top-surface first area 334 may be a curved surface or a combination of an inclined surface and a curved surface. The top-surface second area 335 is a planar area extending in a direction perpendicular to the axial direction.

In a part of the top surface of the rib 33, the top-surface first area 334 and the top-surface second area 335 are arranged in the radial direction. In the part in which the top-surface first area 334 and the top-surface second area 335 are arranged in the radial direction, the top-surface first area 334 is disposed on the outer side of the top-surface second area 335 in the radial direction. The top-surface first area 334 extends rearward from the end on the front side in the radial direction R of the impeller 1 and is connected to the top-surface second area 335 before it reaches the end on the rear side.

Here, the top-surface first area 334 may extend from the end on the front side in the rotational direction R of the impeller 1 to the end on the rear side. The entire top surface of the rib 33 may be the top-surface first area 334. The entire top surface of the rib 33 may be the top-surface second area 335.

As illustrated in FIG. 8, at least a part of the top surface of the rib 33 extends downward toward the outer side in the radial direction. According to this configuration, it is possible to smoothly guide the air flow 300 in consideration of a centrifugal force which is generated by rotation of the impeller 1 on the top surface of the rib 33. Accordingly, when the impeller 1 rotates, it is possible to reduce air-blowing resistance and to enhance air-blowing efficiency.

In this embodiment, a part of the top surface of the rib 33 extends downward toward the outer side in the radial direction. Specifically, the top-surface first area 334 includes an inclined surface extending downward toward the outer side in the radial direction. Here, the top-surface first area 334 may include a curved surface extending downward toward the outer side in the radial direction. The top-surface first area 334 may include a combination of an inclined surface and a curved surface extending toward the outer side in the radial direction. The configuration extending downward toward the outer side in the radial direction may be provided in an area other than the top-surface first area 334 on the top surface of the rib 33. The entire top surface of the rib 33 may extend downward toward the outer side in the radial direction. The top surface of the rib 33 may not include an area extending downward toward the outer side in the radial direction.

As illustrated in FIG. 8, the rib 33 includes a first radial inner end surface 336 and a second radial inner end surface 337. In this embodiment, the first radial inner end surface 336 is an end surface that is disposed on the innermost side in the radial direction of the rib 33. Specifically, the first radial inner end surface 336 includes a curved surface which is convex inward in the radial direction and two planes which are adjacent to the curved surface in the circumferential direction. Here, the first radial inner end surface 336 may be a single curved surface or a planar surface.

The second radial inner end surface 337 is disposed on the outer side of the first radial inner end surface 336 in the radial direction below the first radial inner end surface 336. In this embodiment, the second radial inner end surface 337 is a curved surface which is concave outward in the radial direction. The second radial inner end surface 337 may be a planar surface or the like. The second radial inner end surface 337 is disposed on the inner side of the bottom-surface first area 332 in the radial direction.

The bottom surface of the rib 33 includes a bottom-surface third area 338 that connects the first radial inner end surface 336 and the second radial inner end surface 337 on the inner side of the bottom-surface first area 332 in the radial direction. Specifically, the bottom-surface third area 338 extends in a direction perpendicular to the axial direction and includes two planes having a step difference therebetween in the axial direction. Here, the bottom-surface third area 338 may be a single plane or a curved surface extending in the axial direction.

The rib recessed part 331 that is recessed upward in the axial direction is provided in the bottom-surface third area 338. That is, on the bottom surface of the rib 33, the rib recessed part 331 that is recessed upward in the axial direction is provided on the inner side of the bottom-surface first area 332 in the radial direction.

FIG. 9 is a longitudinal sectional view illustrating a relationship between the stator 22 and the housing 3. FIG. 9 illustrates a part of the relationship between the stator 22 and the housing 3. At least a part of the bottom-surface third area 338 is in contact with the top surface of the stator core 221. In this embodiment, a part of the bottom-surface third area 338 is in contact with the top surface of the stator core 221 of the stator 22. According to this configuration, the position in the axial direction of the upper housing 3U can be determined by the stator core 221.

At least a part of the top surface of the leg-part upper wall part 363 is in contact with the bottom surface of the stator core 221. Accordingly, the position in the axial direction of the lower housing 3L can be determined by the stator core 221.

As illustrated in FIG. 9, the stator 22 and the rib 33 are fixed by the fixing member 7 of which a part is disposed in the rib recessed part 331. Specifically, the fixing member 7 is inserted into the leg-part hole 364, the stator core hole 2213, and the rib recessed part 331 and fixes the stator 22 and the housing 3. According to this configuration, the housing 3 and the stator 22 can be strongly fixed using the rib 33.

FIG. 10 is a transverse sectional view illustrating a relationship between the insulator 222 and the upper housing 3U. As illustrated in FIG. 10, the insulator 222 includes a first insulator wall part 2221 and a second insulator wall part 2222. The first insulator wall part 2221 extends in a direction crossing the circumferential direction. In this embodiment, the insulator 222 includes an annular insulator circumferential part 2223 that is disposed on the top surface of the core back 2211. The first insulator wall part 2221 extends upward in the axial direction from the top surface of the insulator circumferential part 2223. Here, the first insulator wall part 2221 may extend, for example, outward in the radial direction from the insulator circumferential part 2223.

The second insulator wall part 2222 faces the first insulator wall part 2221 in the circumferential direction. In this embodiment, the second insulator wall part 2222 extends upward in the axial direction from the top surface of the insulator circumferential part 2223. The second insulator wall part 2222 has the same shape as the first insulator wall part 2221. Here, the second insulator wall part 2222 may have a shape different from that of the first insulator wall part 2221.

The rib 33 is disposed between the first insulator wall part 2221 and the second insulator wall part 2222 in the circumferential direction. The rib 33 may be in contact with at least one of the first insulator wall part 2221 and the second insulator wall part 2222. The rib 33 may not be in contact any of the first insulator wall part 2221 and the second insulator wall part 2222, but is disposed close to the first insulator wall part 2221 and the second insulator wall part 2222 according to an embodiment of the disclosure. According to this configuration, the position in the circumferential direction of the upper housing 3U and the stator 22 can be determined by the rib 33.

In this embodiment, the number of ribs 33 is three. In correspondence therewith, three sets of the first insulator wall part 2221 and the second insulator wall part 2222 facing each other in the circumferential direction are arranged in the circumferential direction. Accordingly, the position in the circumferential direction of each rib 33 can be determined. Here, the number of sets of the first insulator wall part 2221 and the second insulator wall part 2222 facing each other in the circumferential direction may be one.

In this embodiment, in the circumferential direction between the first insulator wall part 2221 and the second insulator wall part 2222 facing each other in the circumferential direction, a cutout part 2224 obtained by cutting out at least a part of the insulator circumferential part 2223 is provided. At least a part of the bottom-surface third area 338 of the rib 33 is in contact with the top surface of the stator core 221 which is exposed from the cutout part 2224.

FIG. 11 is a schematic longitudinal sectional view illustrating a first modified example of the blower 100 according to the embodiment of the disclosure. FIG. 11 illustrates a part of a sectional view of an upper housing 3UA according to the first modified example. Similarly to the above-mentioned embodiment, the upper housing 3UA includes a first housing part 31A, a second housing part 32A, and a rib 33A. The bottom surface of the rib 33A includes a bottom-surface first area 332A extending downward toward the front side in the rotational direction R of the impeller 1.

As illustrated in FIG. 11, at least a part of the bottom surface of the rib 33A extends downward toward the outer side in the radial direction. In this modified example, a part of the bottom surface of the rib 33A extends downward toward the outer side in the radial direction. Specifically, the bottom-surface first area 332A includes an inclined surface extending downward toward the outer side in the radial direction. Here, the bottom-surface first area 332A may include a curved surface extending downward toward the outer side in the radial direction. The bottom-surface first area 332A may include a combination of an inclined surface and a curved surface extending downward toward the outer side in the radial direction.

According to this configuration, it is possible to smoothly guide the air flow 300 in consideration of a centrifugal force which is generated by rotation of the impeller 1 on the bottom surface of the rib 33A. Accordingly, when the impeller 1 rotates, it is possible to reduce air-blowing resistance and to enhance air-blowing efficiency.

FIG. 12 is a schematic longitudinal sectional view illustrating a second modified example of the blower 100 according to the embodiment of the disclosure. FIG. 12 is a sectional view of an upper housing 3UB according to the second modified example and corresponds to a sectional view taken along line X-X in FIG. 6. In FIG. 12, reference sign R represents the rotational direction of the impeller 1.

Similarly to the above-mentioned embodiment, the upper housing 3UB includes a first housing part 31B and a rib 33B. The bottom surface of the rib 33B includes a bottom-surface first area 332B extending downward toward the front side in the rotational direction R of the impeller 1. The bottom surface of the rib 33B includes a bottom-surface second area 333B extending downward toward the front side in the rotational direction R of the impeller 1 on the front side of the bottom-surface first area 332B in the rotational direction R of the impeller 1. The top surface of the rib 33B includes a top-surface first area 334B extending downward toward the front side in the rotational direction of the impeller 1.

A rib penetrating hole 339 that extends in the axial direction is provided in the rib 33B. In this modified example, the rib penetrating hole 339 is disposed on the front side of the bottom-surface first area 332B in the rotational direction R of the impeller 1. The rib penetrating hole 339 is disposed on the rear side of the bottom-surface second area 333 bottom-surface second area 333B and the top-surface first area 334B in the rotational direction R of the impeller 1. The bottom-surface second area 333B may not be provided. The top-surface first area 334B may not be provided and the top surface of the rib 33B may include, for example, only a planar surface extending in a direction perpendicular to the axial direction.

According to this modified example, the air flow 300 which is generated by rotation of the impeller 1 can be guided downward through the rib penetrating hole 339. Accordingly, it is possible to reduce air-blowing resistance due to the rib 33B.

FIG. 13 is a schematic transverse sectional view illustrating a third modified example of the blower 100 according to the embodiment of the disclosure. FIG. 13 is a diagram illustrating a part of a relationship between a rib 33C and a stator core 221C. Similarly to the above-mentioned embodiment, an upper housing 3UC includes a first housing part 31C and a rib 33C. A stator 22C includes a stator core 221C in which a core recessed part 2214 which is recessed inward in the radial direction is provided on a radial outer surface thereof.

A pair of recessed-part wall surface parts 2215 facing each other in the circumferential direction is formed on the radial outer surface of the stator core 221C. The pair of recessed-part wall surface parts 2215 extends in the axial direction. The core recessed part 2214 is formed between the pair of recessed-part wall surface parts 2215 in the circumferential direction. Two ends in the axial direction of the core recessed part 2214 are open. A part of the rib 33C is inserted into the core recessed part 2214. Two ends in the circumferential direction in the part of the rib 33C inserted into the core recessed part 2214 are in contact with or are close to the pair of recessed-part wall surface parts 2215. According to this configuration, the positions of the upper housing 3UC and the stator 22C in the circumferential direction can be determined by the rib 33C and the core recessed part 2214.

In this modified example, the first insulator wall part 2221 and the second insulator wall part 2222 facing each other in the circumferential direction may not be provided in the insulator 222.

An example of a vacuum cleaner 200 to which the blower 100 according to this embodiment is applied will be described below. FIG. 14 is a perspective view of the vacuum cleaner 200 according to an embodiment of the disclosure. As illustrated in FIG. 14, the vacuum cleaner 200 includes the blower 100. The vacuum cleaner 200 is a so-called stick type electric vacuum cleaner. The vacuum cleaner 200 including the blower 100 may be another type electric vacuum cleaner such as a robot type, a canister type, or a handy type.

The vacuum cleaner 200 includes a housing 201 in which an intake part 202 and an exhaust part 203 are provided on a bottom surface and a top surface thereof. The vacuum cleaner 200 includes a rechargeable battery (not illustrated) and operates with electric power which is supplied from the battery. Here, the vacuum cleaner 200 may include a power supply cord and operate with electric power which is supplied via the power supply cord connected to a power outlet provided on a wall of a living room.

An air passage (not illustrated) connecting the intake part 202 and the exhaust part 203 is formed in the housing 201. In the air passage, a dust collector (not illustrated), a filer (not illustrated), and a blower 100 are sequentially arranged from the intake part 202 (upstream) to the exhaust part 203 (downstream). Refuse such as dust included in air flowing in the air passage is caught by the filter and is collected in the dust collector formed in a container shape. The dust collector and the filter are provided to be detachable from the housing 201.

A holding part 204 and an operation part 205 are provided in an upper part of the housing 201. A user can hold the holding part 204 and move the vacuum cleaner 200. The operation part 205 includes a plurality of buttons 205 a. A user sets the operation of the vacuum cleaner 200 by operating the buttons 205 a. For example, it is instructed to start driving of the blower 100, to stop driving thereof, to change a rotation speed thereof, and the like by operating the buttons 205 a. A rod-shaped suction tube 206 is connected to the intake part 202. A suction nozzle 207 is attached to an upstream end of the suction tube 206 to be detachable from the suction tube 206. The upstream end of the suction tube 206 is a lower end of the suction tube 206 in FIG. 14.

In this embodiment, the vacuum cleaner 200 includes the blower 100 that can enhance air-blowing efficiency of the vacuum cleaner 200. Accordingly, according to this embodiment, it is possible to enhance performance of the vacuum cleaner 200.

Various technical features disclosed in this specification can be modified in various forms without departing from the gist of the technical idea thereof. A plurality of embodiments and a plurality of modified examples described in this specification may be combined for implementation if possible.

The disclosure can be used for, for example, a blower and a vacuum cleaner including the blower.

Features of the above-described embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.

While embodiments of the disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the disclosure. The scope of the disclosure, therefore, is to be determined solely by the following claims. 

What is claimed is:
 1. A blower comprising: an impeller that is able to rotate around a center axis extending vertically; a motor that includes a rotor connected to the impeller and a stator facing the rotor in a radial direction; and a housing that accommodates at least a part of the motor, wherein the housing includes a first housing part that is disposed on an outer side in the radial direction of the stator, a radial inner surface thereof forming a flow passage, a second housing part that is disposed on an inner side in the radial direction of the first housing part, and a rib that connects the first housing part and the second housing part, and wherein a bottom surface of the rib includes a bottom-surface first area that extends downward toward a front side in a rotational direction of the impeller.
 2. The blower according to claim 1, wherein at least a part of a top surface of the rib extends downward toward the front side in the rotational direction of the impeller.
 3. The blower according to claim 1, wherein at least a part of a top surface of the rib extends downward toward an outer side in the radial direction.
 4. The blower according to claim 1, wherein the bottom surface of the rib includes a bottom-surface second area on the front side of the bottom-surface first area in the rotational direction of the impeller, and the bottom-surface second area extends upward toward the front side in the rotational direction of the impeller.
 5. The blower according to claim 4, wherein a distance in the axial direction between an upper end and a lower end of the bottom-surface first area is greater than a distance in the axial direction between an upper end and a lower end of the bottom-surface second area.
 6. The blower according to claim 1, wherein at least a part of the bottom surface of the rib extends downward toward an outer side in the radial direction.
 7. The blower according to claim 1, further comprising a plurality of stationary vanes that is arranged in the circumferential direction above the rib.
 8. The blower according to claim 1, wherein the first housing part, the second housing part, and the rib are formed of a single member.
 9. The blower according to claim 1, wherein a rib recessed part that is recessed upward in the axial direction is provided on the bottom surface of the rib and on the inner side of the bottom-surface first area in the radial direction, and wherein the stator and the rib are fixed by a fixing member of which a part is disposed in the rib recessed part.
 10. The blower according to claim 1, wherein a rib-penetrating hole that extends in the axial direction is provided in the rib.
 11. The blower according to claim 1, wherein the stator includes a stator core, and an insulator that covers at least a part of the stator core, wherein the insulator includes a first insulator wall part that extends in a direction crossing the circumferential direction, and a second insulator wall part that faces the first insulator wall part in the circumferential direction, and wherein the rib is disposed between the first insulator wall part and the second insulator wall part in the circumferential direction.
 12. The blower according to claim 1, wherein the rib includes a first radial inner end surface, and a second radial inner end surface that is disposed on an outer side of the first radial inner end surface in the radial direction below the first radial inner end surface, wherein the bottom surface of the rib includes a bottom-surface third area that connects the first radial inner end surface and the second radial inner end surface on an inner side of the bottom-surface first area in the radial direction, and wherein at least a part of the bottom-surface third area is in contact with a top surface of the stator core.
 13. The blower according to claim 1, wherein the stator includes a stator core in which a core recessed part which is recessed inward in the radial direction on a radial outer surface thereof is provided, and wherein a part of the rib is inserted into the core recessed part.
 14. A vacuum cleaner comprising the blower according to claim
 1. 